Rotation phenomenon observed in uncured multiaxial prepreg laminates during compaction

Abstract

The compaction deformation of uncured thermoset prepregs plays a pivotal role in determining the dimensional accuracy of the final composite parts in the hot press-forming process. This work delves into the investigation of in-plane rotation deformation occurred in multiaxial prepreg laminates during compaction. The influencing factors and deformation mechanism of this in-plane rotation phenomenon were elucidated through experiments and the finite element method. Experimental results show that in-plane rotation occurred in multiaxial laminates, with an average in-plane rotation angle exceeding 6.0° in laminates with continuous stacking pitch angles. The rotation angle increased when the mono-layer thickness was doubled. Finite element analysis reveals that the in-plane rotation was dominated by the interply shear stress between prepreg layers, which is induced by the difference in adjacent layer expansion direction. These findings offer useful insights into the lay-up design and deformation control in the hot press-forming process.